Disk drive manufacturers typically test manufactured disk drives for compliance with a collection of requirements. Test equipment and techniques exist for testing large numbers of disk drives serially or in parallel. Manufacturers tend to test large numbers of disk drives simultaneously in batches. Disk drive testing systems typically include one or more racks having multiple test slots that receive disk drives for testing.
The testing environment immediately around the disk drive is closely regulated. Minimum temperature fluctuations in the testing environment are critical for accurate test conditions and for safety of the disk drives. The latest generations of disk drives, which have higher capacities, faster rotational speeds and smaller head clearance, are more sensitive to vibration. Excess vibration can affect the reliability of test results and the integrity of electrical connections. Under test conditions, the drives themselves can propagate vibrations through supporting structures or fixtures to adjacent units. This vibration “cross-talking,” together with external sources of vibration, contributes to bump errors, head slap and non-repetitive run-out (NRRO), which may result in lower test yields and increased manufacturing costs.
Current disk drive testing systems use an operator, a robotic arm, or a conveyer belt to individually feed disk drives to a transfer location for loading into the testing system for testing. A robotic arm of the testing system individually retrieves the disk drives from the transfer location and loads them in test slots for testing.